Please Note: the cache is not at the above co-ordinates, but the posted co-ordinates are where you can park and walk from there to the cache.
In order to discover the cache co-ordinates you must first solve the Sudoku puzzle. It is a slight spin on the classic Sudoku because it uses the letters A through to I rather than the numbers 1 through to 9. In every other way it is the same. Solve the puzzle in the comfort of your home, then use the solution checker to make sure you have solved it correctly, and head out to claim your smiley! The Sudoku puzzle can be found in the images gallery. If you want to print out a blank Sudoku page to use for solving here is a link: https://urbanrim.org.uk/blankgrid.htm
To solve, place a letter into each empty box so that each row (across), each column (down) and each small 9-box square within the larger diagram (there are 9 of these) will contain every letter from A through I. In other words, no letter can appear more than once in any row, column, or smaller 9-box square.
Once you have filled in all the squares, identify the letter in each of the coloured boxes (red, blue, yellow, green and purple) Then using A=1, B=2 etc through to I=9, convert the letter in each coloured box to a number and then use that to complete the coordinates.
Final coordinates: N59 34.red; red; green W133 42.yellow; blue; purple